1. Field of the Invention
The invention pertains to vane type indexable signs and transmissions therefor which permit sequential vane operation.
2. Description of the Related Art
Changeable signs of large dimension consisting of a plurality of side-by-side vanes, usually vertically oriented, wherein the complete sign face is defined by the combination of vane faces have been used for some time as evidenced by U.S. Pat. Nos. 1,461,047; 1,785,204; 1,865,725 and 5,161,421. Changeable signs of this type mount a plurality of vanes, usually three in number, on a single sign support shaft which is sequentially indexed through 120.degree. of rotation to permit three different sign faces to be sequentially visible for each complete revolution of the sign support shaft. Usually, all of the vanes constituting the sign are simultaneously rotated wherein the entire sign face will be simultaneously changed, and three related or unrelated sign faces can be operated by the same mechanism.
With changeable vane type signs of this type, a transmission is normally utilized with each set of vanes commonly mounted upon a sign support shaft. As the transmissions constituting the sign vane supports are interconnected such as shown in U.S. Pat. No. 5,511,330, all of the vanes constituting the sign are normally rotated simultaneously.
In order to generate interest in the sign's message, it is desirable to sequentially rotate the adjacent vanes whereby the sign message is revealed sequentially or in a "wave" manner, and previously, sign operating mechanism to produce a wave action and yet maintain each vane in a stationary locked manner during viewing has not been available.